Modern communication devices can comprise an antenna connected to a signal path that is susceptible to detuning due to unexpected external influences. To retune the antenna and to improve transmission and/or reception, the mobile communication device can comprise an antenna tuner with an impedance matching network for adaptive impedance matching. However, the actual impedance of the signal path and/or of the antenna must be known.
Further, mobile communication devices operate with different transmission systems and in different frequency bands. Multi-transmission system devices and multi-frequency devices render the determination of the actual impedance of the signal path and/or of the antenna problematic.
Conventional impedance detectors are known, e.g. from U.S. Pat. No. 8,111,111.
What is needed is an impedance detector that works well with different transmission systems and different frequency bands, and that allows to determine the actual impedance and/or the mismatch of the actual impedance compared to a desired impedance.